Planoorapii co



C. A. MACDONALD AND M. P. DOUGHERTY.

PRESS GUARD.

APPLICATION FILED AUG-I7. 916.

I 1,314,750; Patented Sept. 2, 1919.

3 SHEETS-SHEET I.

BY v

ma COLUMBIA PMNOGIIAPII 10., WASHINGTON. u. c.

c. A. MAcDONALD AN D M. P. DOUGHERTY.

PRESS GUARD.

APPLICATION FILED AUG-H. 19I6.

Patented Sept. 2, 1919.

3 SHEETS- SHEET 2.

WITNESSES: INVENTORS Cha les xifiwfionaZaZ 5590M mm;

1m: COLUMBIA PLANOGRANI c0 \vAiNlNuTON. D. c.

C. A. MACDONALD AND M. P. DOUGHERTY.

FRESS GUARD.

APPLICATION FILED AUGJI. I9I6.

M Na 9mm W4 &m 2% mm w 5 A u j 0 .M a w W- 1 r Q F 0 5 4 1 1 WITNESSES:

like,-.that Wlll' be sure in its operation,

the; reliability of the apparatus "tomatic 'actuations performed itself, if need be, and to accomplishing this best UNITED STATES PATENT OFFICE.

CHARLES ADDISON MACDONALD AND 1 P. ,DOTIGHERTY, OF ROCHESTER, NEW YORK, ASSIG-NORS, BY DIRECT AND MESNE ASSIGNMENTS, OF ONE-HALF TO CHARLES J. PEMBROKE AND ONE-HALF TO FRANK KEIPER, BOTH OF ROCHESTER, NEW YORK.

rnnss-euAnnf' Specification of Letters Patent.

Patented Sept. 2, 1919.

'of New York, have invented certain new and useful Improvements in Press-Guards; and we do hereby declare the following to be. a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specifica tion, and to the reference-numerals marked.

thereon.

Our present invention relates to safety. ap-

pliances for machinery, and it has for its object to provide a simple, convenient and efficient guard for punch presses and thg will offer an infallible preventive to the in- 'sertion of the hand of the operative'into the dangerous'region of the press when the ram orequivalent part is descending. The improvements are directed toward perfecting by the ram object while still retaining a certain latitude i-n operatingthe pressunder circumstances wherein the safety appliance or guard can thesewand other ends the invention consists certain improvements 'and combinations of'parts, all 'as will be hereinafter more fully described, the novel features being pointed out in thec'laims at the end of the specification. r In the drawings: I

Figure 1 is a front elevationof the upper ortion of a" punch press provided with a safety appliance constructed in accordance with andillustrating one embodiment of our i I reasons the ram repeats its descent without an advertent actuation of thetreadle by the invention ;1

Fig. 2' is a side elevation of the press and -guard;

Fig.6 is a reduced front elevationof the .safety appliance with the guard in operative position;

' Fig. kisa horizontal section taken sub- Similar reference numerals in theseveral figures indicate the same parts.

rIn the present embodiment of the inven- H tion, the *guard'is of the type which swings back and-forth in a vertical 'plane in front through au- 7 be momentarily dispensed with. To

detail section taken-'substam and the other consists in connecting up the guard to be moved by the ram itself during the initial part of its down stroke. By the first of these methods,the movement of the guard, while rapid, is not so abrupt as to result in an unduly harsh contact with a mans arm in case it is in the way, but also this method does not result in an infallible safety appliance, as, for instance, the clutch may stick, causing a repetition of the movement of the ram with one actuation of the treadle. The guard being released and the ram being on the reverse stroke, the operator hasno reason to expect that it will immediately descend again before he again presses the treadle, and it is in ]l'lSt such an emergency that an accident is apt to occur. -On the other hand, the operation of the guard by the ram itself during the down stroke, while sure, is abrupt, particularly with a quick acting press, so that the operator is exposed to unnecessary roughness: in the forcible ejection of his arm orhand when in the danger zone.

In the practice of our present invention,

we retain the desirable features of both methods While eliminating the undesirable 1 features, by operating thesame guardarm .by means of the clutch treadle in ordinary running when everything is acting properly,

and by the ram itself'in case of an'emergency, where the clutch sticks, or for other operator. We also provide means whereby the'guard is locked operativeposition while the ram is down, and isreleased by the lat- 'ter'on the return stroke unless it is desired to voluntarily release it for certain 11 oses. Referring'more particularly to the rawings, and to Figs. 1 and 2 thereof, the press to tached comprises'a frame 1 above a bed 2, in which'frame a ram 3 is guided at 4 to reciprocate vertically on the crank 5 of a shaft 6. I .7 indicates a male die carried by the ram as .itmoves toward and fromthe which our appliance is shown atbed 2 to cooperate with a female die 8 on the'latter, 9 being the die clamp. The shaft '6 is'rotated by a drive wheel 10'through the medium ofaclutch" 11 which, when actuated, causes the ram 3 to make one reciprocation,

namely, to approach the bed 2 and return to the elevated position shown in Fig. 1. The clutch is actuated (Fig. 2') by a pul'1'rod12 connected to a lever 13 pivoted at 14 at the side of the frame 1. A link 15 is connected tothe lever13 and to a lever Y16',-which latter is'in turn connected. by-a link.17 to afoot treadle 18pivoted at-l9 to thebaseiframe 20 r *of-the-machine .The:foot -*treadle 18' isnormally held raised by a. spring. .21, and when depressed; it rocks-the lever 13: downwardly,

"asissclear from an inspectionof Fig. 2.

.5 The .safety appliance is carried by. a bridge22supported on bracketsr23 at each p'iece spanstheram 3 and its guides. .A guard arm 24wis pivoted, centrally of the bridge-22 at 25 to-vibrate toward the right from theinoperative position of Fig. 1 in a'verticals plane. A vane or shield 26; car-- ried at the lower end ofithe arm assumes the" positionshown in Fig. '3 when the-guard is operated and obstructs access from the front to the dangerous 'region between the dies moving to this operative position, the guard 7 and 8 on the ram and-bed respectively. In

will thrust the armor-hand of the operator aside if it isin the danger zone,fand to prevent bruising the flesh the vane or arm is preferably provided with a rubber or other pad 27 at the right or" advancing edge. 7 f The arm orle'ver 24 is pivoted to a link 28 proceedingto the right therefrom at its npperendabove the pivot- 25 Pivote'd to the linkat 29 isthe lower arm of aleverBO 'pivoted at31 to the'b-ridge 22 to: vibrate in a plane parallel with thatof the guard-lever'24, andthe lever is in turn pivoted f at" 32 on =its" iupper* arm fto a a vertical link 33 having an adjustable slot and "pin'con- 'nect'ion-at 34 with the forward endof lever Fromthis it will be seen that" as the le- 'v'er13i's drawn downwardly by the ,1 foot treadle 18 in actuating the clutch 11 to cause reciprocation of theram '3', the guard arm 2 4andshield 26 will-be rocked from' the normal position' of Figs. 1 andf2'to the operative position of Fig; 3, inffront of the dies ;7 and 8, and in-doi'ng'so willthrow.

out the operators"han'd,-if inthe way, previ- 'ous to the descent of the' ram. Thejzlutch 11' is inpt thrown in-1 immediately upon; the initi al movement of the "lever'x13,"but the {guard isim'mediately m'oved', so that" the {g ard "reaches operative position beforethe ram descends, the cl'utch' taking "its grip only during ithe last fractional part of the moveof "the 'tt'eadle and l ver-13. *{Being "imanually operated, theguard'jinoves quickly "butrathergently to i position, and the were.

side-of the upper frame 1, which bridge tor suffers no discomfort from guard is in inoperative position, asin Fig- 1, this roller lies in the path of an L-shaped abutment 38, mounted for. vertical adj ustment on the-ram 3 by bolts .39.:exte1iding. through a slot v therein. .2 The I offset of: the crank 'ar'm 36:is-such1that, during the "first partof the movement of the ram, it will be engaged by the abutment :38 and carried far enough to rock :the .fguard-xarm 24 to 'operative position before the dies '7 and Shav'e come close enough togetherato Work injury to the hand of the operator, ifnlying 1 y between them. :As before explained, the guard moves underthe'influence of the f'oot treadle" before there is any movemention .theql 1 part of the ram,"so that if thewfoot'trea'dle connection is working all right, the stop 38 does not engage "the roller. 37 at=all," but 'the latter; is moved in advance of it. -There-, fof're; this automatic actuation ofthe guard,

by the ram occurs only :in an: emergency," and in the event that the clutch-"ll-sticks,

or for other reasons the ram repeatsitsidecent i d pendently of the treadle'. There is henfce nocontinuous noisy and wearing battering of the guard mechanism bythe rami during the normal operation of the i press,

ed parts, including the guard mechanism, 'but to 'reinforce its action: and insure prompt return of the guard ar'm24 to inoperative position we prefer 'to -co-nriectwa 3 The-spring 21 of theihtreadle, of co'urse, I has a tendency to return a11+of the connect-2 spring 41 with the lever 30 and with-aifixed part of the frame 1, such'asthe arm on the bridge piece 22 (Fig.1). "We prefer to also provide "guard in operative position-until the-Iram has proceeded upwardly againfaway from forlockingthe g the bed, so that the guard cannot'be brushed aside once'it'has reachedfits operative position. To this end, a sma ll shaft 43' is journaled in cars 44 on thebridge piece 22,"and

carries fixed thereto alatc-h arm '45 and a trip finger 46. The latch arm 45 t'islnormany yieldingly lieldbyf a' 'spring 47, tendin'g'jto rotate the shaft 43'to a position m which it will automatically engagewith a notch 48 in thelink28 of'gu'ard arm 24' when i the latter is rocked"sufliciently andlock it in operative'position; [As before stated,

with the foot treadle actuation of the guard, thiswil'l occur before the ram 'start's its deram on the abutment 38, in descending later, passes the trip finger 46 because of the yielding of a cam pin 50 on the latter having a spring 51 behind it. When the ram moves upwardly again, however, the trip 49 engages the under side of the pin 50, which latter does not then yield, and the trip finger 46 is rocked upwardly, rotating the shaft 43 and carrying the latch arm 45 against the tension of spring 47, out of locking engagement with the notch 48 on the link 28 of guard arm 24, permitting the latter to be withdrawn to inoperative position by its spring 41.

If, 1n the preliminary adjustment of the dies, for instance, it is desired to have access to them While the dies are in contact, or very near it the latch 45 is free to be released by hand, but of course the stop 38 must be taken ofl or first adjusted'to its upward extreme in order not to confine the movement of the crank 36 and roller 37.

We claim as our invention:

In a safety device for a punch press, the combination of a bridge, a vertically disposed guard pivoted to said bridge, a crank, a link connecting said crank to the guard, means for rocking said crank from the treadie and thereby rocking said guard through said link, a crank extending laterally from said guard, and a horizontal abutment carried on the ram of the press which makes contact with said crank for the purpose of rocking it and moving the guard as the ram descends.

C. ADDISON MACDONALD. MARTIN P. DOUGHERTY. Witnesses:

P. WESLEY HART, CLAYTON L. JENKS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of ratents, Washington, D. G. 

